Mid-wave infrared p+-B-n InAs/InAsSb type-II superlattice photodetector with an AlAsSb/InAsSb superlattice barrier

Mid-wavelength infrared InAs/InAsSb type-II superlattice p+-B-n photodetectors are demonstrated. An AlAsSb/InAsSb superlattice barrier structure is introduced in order to reduce the bias dependency of optical efficiency. The photodetector exhibits a cut-off wavelength of ∼5.0 µm at 150 K. At 150 K and −100 mV applied bias, the photodetector exhibits a dark current density of 1.2 × 10-4 A/cm2, a quantum efficiency of 29% at peak responsivity (∼4.1 µm), and a specific detectivity of 1.2 × 1011 cm•Hz1/2/W.